Re: [PATCH V3 15/22] LoongArch: Add elf and module support

diff --git a/arch/loongarch/include/asm/cpufeature.h b/arch/loongarch/include/asm/cpufeature.h
new file mode 100644
index 000000000000..7e4c6a769830
--- /dev/null
+++ b/arch/loongarch/include/asm/cpufeature.h

@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * CPU feature definitions for module loading, used by
+ * module_cpu_feature_match(), see uapi/asm/hwcap.h for LoongArch CPU features.
+ *
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+
+#ifndef __ASM_CPUFEATURE_H
+#define __ASM_CPUFEATURE_H
+
+#include <uapi/asm/hwcap.h>
+#include <asm/elf.h>
+
+#define MAX_CPU_FEATURES (8 * sizeof(elf_hwcap))
+
+#define cpu_feature(x)         ilog2(HWCAP_ ## x)
+
+static inline bool cpu_have_feature(unsigned int num)
+{
+       return elf_hwcap & (1UL << num);
+}
+
+#endif /* __ASM_CPUFEATURE_H */

diff --git a/arch/loongarch/include/asm/elf.h b/arch/loongarch/include/asm/elf.h
new file mode 100644
index 000000000000..9f8c2ab1a206
--- /dev/null
+++ b/arch/loongarch/include/asm/elf.h

@@ -0,0 +1,308 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_ELF_H
+#define _ASM_ELF_H
+
+#include <linux/auxvec.h>
+#include <linux/fs.h>
+#include <linux/mm_types.h>
+
+#include <uapi/linux/elf.h>
+
+#include <asm/current.h>
+
+/* ELF header e_flags defines. */
+
+/* The ABI of a file. */
+#define EF_LARCH_ABI_LP32              0x00000001      /* LP32 ABI.  */
+#define EF_LARCH_ABI_LPX32             0x00000002      /* LPX32 ABI  */
+#define EF_LARCH_ABI_LP64              0x00000003      /* LP64 ABI  */
+#define EF_LARCH_ABI                   0x00000003
+
+/* LoongArch relocation types used by the dynamic linker */
+#define R_LARCH_NONE                           0
+#define R_LARCH_32                             1
+#define R_LARCH_64                             2
+#define R_LARCH_RELATIVE                       3
+#define R_LARCH_COPY                           4
+#define R_LARCH_JUMP_SLOT                      5
+#define R_LARCH_TLS_DTPMOD32                   6
+#define R_LARCH_TLS_DTPMOD64                   7
+#define R_LARCH_TLS_DTPREL32                   8
+#define R_LARCH_TLS_DTPREL64                   9
+#define R_LARCH_TLS_TPREL32                    10
+#define R_LARCH_TLS_TPREL64                    11
+#define R_LARCH_IRELATIVE                      12
+#define R_LARCH_MARK_LA                                20
+#define R_LARCH_MARK_PCREL                     21
+#define R_LARCH_SOP_PUSH_PCREL                 22
+#define R_LARCH_SOP_PUSH_ABSOLUTE              23
+#define R_LARCH_SOP_PUSH_DUP                   24
+#define R_LARCH_SOP_PUSH_GPREL                 25
+#define R_LARCH_SOP_PUSH_TLS_TPREL             26
+#define R_LARCH_SOP_PUSH_TLS_GOT               27
+#define R_LARCH_SOP_PUSH_TLS_GD                        28
+#define R_LARCH_SOP_PUSH_PLT_PCREL             29
+#define R_LARCH_SOP_ASSERT                     30
+#define R_LARCH_SOP_NOT                                31
+#define R_LARCH_SOP_SUB                                32
+#define R_LARCH_SOP_SL                         33
+#define R_LARCH_SOP_SR                         34
+#define R_LARCH_SOP_ADD                                35
+#define R_LARCH_SOP_AND                                36
+#define R_LARCH_SOP_IF_ELSE                    37
+#define R_LARCH_SOP_POP_32_S_10_5              38
+#define R_LARCH_SOP_POP_32_U_10_12             39
+#define R_LARCH_SOP_POP_32_S_10_12             40
+#define R_LARCH_SOP_POP_32_S_10_16             41
+#define R_LARCH_SOP_POP_32_S_10_16_S2          42
+#define R_LARCH_SOP_POP_32_S_5_20              43
+#define R_LARCH_SOP_POP_32_S_0_5_10_16_S2      44
+#define R_LARCH_SOP_POP_32_S_0_10_10_16_S2     45
+#define R_LARCH_SOP_POP_32_U                   46
+#define R_LARCH_ADD8                           47
+#define R_LARCH_ADD16                          48
+#define R_LARCH_ADD24                          49
+#define R_LARCH_ADD32                          50
+#define R_LARCH_ADD64                          51
+#define R_LARCH_SUB8                           52
+#define R_LARCH_SUB16                          53
+#define R_LARCH_SUB24                          54
+#define R_LARCH_SUB32                          55
+#define R_LARCH_SUB64                          56
+#define R_LARCH_GNU_VTINHERIT                  57
+#define R_LARCH_GNU_VTENTRY                    58
+
+#ifndef ELF_ARCH
+
+/* ELF register definitions */
+
+/*
+ * General purpose have the following registers:
+ *     Register        Number
+ *     GPRs            32
+ *     EPC             1
+ *     BADVADDR        1
+ *     CRMD            1
+ *     PRMD            1
+ *     EUEN            1
+ *     ECFG            1
+ *     ESTAT           1
+ *     Reserved        6
+ */
+#define ELF_NGREG      45
+
+/*
+ * Floating point have the following registers:
+ *     Register        Number
+ *     FPR             32
+ *     FCC             1
+ *     FCSR            1
+ */
+#define ELF_NFPREG     34
+
+typedef unsigned long elf_greg_t;
+typedef elf_greg_t elf_gregset_t[ELF_NGREG];
+
+typedef double elf_fpreg_t;
+typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
+
+void loongarch_dump_regs64(u64 *uregs, const struct pt_regs *regs);
+
+#ifdef CONFIG_32BIT
+/*
+ * This is used to ensure we don't load something for the wrong architecture.
+ */
+#define elf_check_arch elf32_check_arch
+
+/*
+ * These are used to set parameters in the core dumps.
+ */
+#define ELF_CLASS      ELFCLASS32
+
+#define ELF_CORE_COPY_REGS(dest, regs) \
+       loongarch_dump_regs32((u32 *)&(dest), (regs));
+
+#endif /* CONFIG_32BIT */
+
+#ifdef CONFIG_64BIT
+/*
+ * This is used to ensure we don't load something for the wrong architecture.
+ */
+#define elf_check_arch elf64_check_arch
+
+/*
+ * These are used to set parameters in the core dumps.
+ */
+#define ELF_CLASS      ELFCLASS64
+
+#define ELF_CORE_COPY_REGS(dest, regs) \
+       loongarch_dump_regs64((u64 *)&(dest), (regs));
+
+#endif /* CONFIG_64BIT */
+
+/*
+ * These are used to set parameters in the core dumps.
+ */
+#define ELF_DATA       ELFDATA2LSB
+#define ELF_ARCH       EM_LOONGARCH
+
+#endif /* !defined(ELF_ARCH) */
+
+#define loongarch_elf_check_machine(x) ((x)->e_machine == EM_LOONGARCH)
+
+#define vmcore_elf32_check_arch loongarch_elf_check_machine
+#define vmcore_elf64_check_arch loongarch_elf_check_machine
+
+/*
+ * Return non-zero if HDR identifies an 32bit ELF binary.
+ */
+#define elf32_check_arch(hdr)                                          \
+({                                                                     \
+       int __res = 1;                                                  \
+       struct elfhdr *__h = (hdr);                                     \
+                                                                       \
+       if (!loongarch_elf_check_machine(__h))                          \
+               __res = 0;                                              \
+       if (__h->e_ident[EI_CLASS] != ELFCLASS32)                       \
+               __res = 0;                                              \
+                                                                       \
+       __res;                                                          \
+})
+
+/*
+ * Return non-zero if HDR identifies an 64bit ELF binary.
+ */
+#define elf64_check_arch(hdr)                                          \
+({                                                                     \
+       int __res = 1;                                                  \
+       struct elfhdr *__h = (hdr);                                     \
+                                                                       \
+       if (!loongarch_elf_check_machine(__h))                          \
+               __res = 0;                                              \
+       if (__h->e_ident[EI_CLASS] != ELFCLASS64)                       \
+               __res = 0;                                              \
+                                                                       \
+       __res;                                                          \
+})
+
+struct loongarch_abi;
+extern struct loongarch_abi loongarch_abi;
+
+#ifdef CONFIG_32BIT
+
+#define SET_PERSONALITY2(ex, state)                                    \
+do {                                                                   \
+       current->thread.abi = &loongarch_abi;                           \
+                                                                       \
+       loongarch_set_personality_fcsr(state);                          \
+                                                                       \
+       if (personality(current->personality) != PER_LINUX)             \
+               set_personality(PER_LINUX);                             \
+} while (0)
+
+#endif /* CONFIG_32BIT */
+
+#ifdef CONFIG_64BIT
+
+#define SET_PERSONALITY2(ex, state)                                    \
+do {                                                                   \
+       unsigned int p;                                                 \
+                                                                       \
+       clear_thread_flag(TIF_32BIT_REGS);                              \
+       clear_thread_flag(TIF_32BIT_ADDR);                              \
+                                                                       \
+       current->thread.abi = &loongarch_abi;                   \
+       loongarch_set_personality_fcsr(state);                          \
+                                                                       \
+       p = personality(current->personality);                          \
+       if (p != PER_LINUX32 && p != PER_LINUX)                         \
+               set_personality(PER_LINUX);                             \
+} while (0)
+
+#endif /* CONFIG_64BIT */
+
+#define CORE_DUMP_USE_REGSET
+#define ELF_EXEC_PAGESIZE      PAGE_SIZE
+
+/*
+ * This yields a mask that user programs can use to figure out what
+ * instruction set this cpu supports. This could be done in userspace,
+ * but it's not easy, and we've already done it here.
+ */
+
+#define ELF_HWCAP      (elf_hwcap)
+extern unsigned int elf_hwcap;
+#include <asm/hwcap.h>
+
+/*
+ * This yields a string that ld.so will use to load implementation
+ * specific libraries for optimization.         This is more specific in
+ * intent than poking at uname or /proc/cpuinfo.
+ */
+
+#define ELF_PLATFORM  __elf_platform
+extern const char *__elf_platform;
+
+/* The regs[11] (a7) holds the syscall number and should not cleared */
+#define ELF_PLAT_INIT(_r, load_addr)   do { \
+       _r->regs[1] = _r->regs[2] = _r->regs[3] = _r->regs[4] = 0;      \
+       _r->regs[5] = _r->regs[6] = _r->regs[7] = _r->regs[8] = 0;      \
+       _r->regs[9] = _r->regs[10] = _r->regs[12] = _r->regs[13] = 0;   \
+       _r->regs[14] = _r->regs[15] = _r->regs[16] = _r->regs[17] = 0;  \
+       _r->regs[18] = _r->regs[19] = _r->regs[20] = _r->regs[21] = 0;  \
+       _r->regs[22] = _r->regs[23] = _r->regs[24] = _r->regs[25] = 0;  \
+       _r->regs[26] = _r->regs[27] = _r->regs[28] = _r->regs[29] = 0;  \
+       _r->regs[30] = _r->regs[31] = 0;                                \
+} while (0)
+
+/*
+ * This is the location that an ET_DYN program is loaded if exec'ed. Typical
+ * use of this is to invoke "./ld.so someprog" to test out a new version of
+ * the loader. We need to make sure that it is out of the way of the program
+ * that it will "exec", and that there is sufficient room for the brk.
+ */
+
+#ifndef ELF_ET_DYN_BASE
+#define ELF_ET_DYN_BASE                (TASK_SIZE / 3 * 2)
+#endif
+
+/* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */
+#define ARCH_DLINFO                                                    \
+do {                                                                   \
+       NEW_AUX_ENT(AT_SYSINFO_EHDR,                                    \
+                   (unsigned long)current->mm->context.vdso);          \
+} while (0)
+
+#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
+struct linux_binprm;
+extern int arch_setup_additional_pages(struct linux_binprm *bprm,
+                                      int uses_interp);
+
+struct arch_elf_state {
+       int fp_abi;
+       int interp_fp_abi;
+};
+
+#define LOONGARCH_ABI_FP_ANY   (0)
+
+#define INIT_ARCH_ELF_STATE {                  \
+       .fp_abi = LOONGARCH_ABI_FP_ANY,         \
+       .interp_fp_abi = LOONGARCH_ABI_FP_ANY,  \
+}
+
+
+extern int arch_elf_pt_proc(void *ehdr, void *phdr, struct file *elf,
+                           bool is_interp, struct arch_elf_state *state);
+
+extern int arch_check_elf(void *ehdr, bool has_interpreter, void *interp_ehdr,
+                         struct arch_elf_state *state);
+
+extern void loongarch_set_personality_fcsr(struct arch_elf_state *state);
+
+#define elf_read_implies_exec(ex, stk) loongarch_elf_read_implies_exec(&(ex), stk)
+extern int loongarch_elf_read_implies_exec(void *elf_ex, int exstack);
+
+#endif /* _ASM_ELF_H */

diff --git a/arch/loongarch/include/asm/exec.h b/arch/loongarch/include/asm/exec.h
new file mode 100644
index 000000000000..00df07ce3529
--- /dev/null
+++ b/arch/loongarch/include/asm/exec.h

@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_EXEC_H
+#define _ASM_EXEC_H
+
+extern unsigned long arch_align_stack(unsigned long sp);
+
+#endif /* _ASM_EXEC_H */

diff --git a/arch/loongarch/include/asm/module.h b/arch/loongarch/include/asm/module.h
new file mode 100644
index 000000000000..6df72c6228e0
--- /dev/null
+++ b/arch/loongarch/include/asm/module.h

@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_MODULE_H
+#define _ASM_MODULE_H
+
+#include <asm-generic/module.h>
+
+#define RELA_STACK_DEPTH 16
+
+struct mod_arch_specific {
+};
+
+#endif /* _ASM_MODULE_H */

diff --git a/arch/loongarch/include/asm/vermagic.h b/arch/loongarch/include/asm/vermagic.h
new file mode 100644
index 000000000000..9882dfd4702a
--- /dev/null
+++ b/arch/loongarch/include/asm/vermagic.h

@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_VERMAGIC_H
+#define _ASM_VERMAGIC_H
+
+#define MODULE_PROC_FAMILY "LOONGARCH "
+
+#ifdef CONFIG_32BIT
+#define MODULE_KERNEL_TYPE "32BIT "
+#elif defined CONFIG_64BIT
+#define MODULE_KERNEL_TYPE "64BIT "
+#endif
+
+#define MODULE_ARCH_VERMAGIC \
+       MODULE_PROC_FAMILY MODULE_KERNEL_TYPE
+
+#endif /* _ASM_VERMAGIC_H */

diff --git a/arch/loongarch/include/uapi/asm/auxvec.h b/arch/loongarch/include/uapi/asm/auxvec.h
new file mode 100644
index 000000000000..5a2200fd75bf
--- /dev/null
+++ b/arch/loongarch/include/uapi/asm/auxvec.h

@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/*
+ * Author: Hanlu Li <lihanlu@loongson.cn>
+ *         Huacai Chen <chenhuacai@loongson.cn>
+ *
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+
+#ifndef __ASM_AUXVEC_H
+#define __ASM_AUXVEC_H
+
+/* Location of VDSO image. */
+#define AT_SYSINFO_EHDR                33
+
+#define AT_VECTOR_SIZE_ARCH 1 /* entries in ARCH_DLINFO */
+
+#endif /* __ASM_AUXVEC_H */

diff --git a/arch/loongarch/include/uapi/asm/hwcap.h b/arch/loongarch/include/uapi/asm/hwcap.h
new file mode 100644
index 000000000000..8840b72fa8e8
--- /dev/null
+++ b/arch/loongarch/include/uapi/asm/hwcap.h

@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _UAPI_ASM_HWCAP_H
+#define _UAPI_ASM_HWCAP_H
+
+/* HWCAP flags */
+#define HWCAP_LOONGARCH_CPUCFG         (1 << 0)
+#define HWCAP_LOONGARCH_LAM            (1 << 1)
+#define HWCAP_LOONGARCH_UAL            (1 << 2)
+#define HWCAP_LOONGARCH_FPU            (1 << 3)
+#define HWCAP_LOONGARCH_LSX            (1 << 4)
+#define HWCAP_LOONGARCH_LASX           (1 << 5)
+#define HWCAP_LOONGARCH_CRC32          (1 << 6)
+#define HWCAP_LOONGARCH_COMPLEX                (1 << 7)
+#define HWCAP_LOONGARCH_CRYPTO         (1 << 8)
+#define HWCAP_LOONGARCH_LVZ            (1 << 9)
+#define HWCAP_LOONGARCH_LBT_X86                (1 << 10)
+#define HWCAP_LOONGARCH_LBT_ARM                (1 << 11)
+#define HWCAP_LOONGARCH_LBT_MIPS       (1 << 12)
+
+#endif /* _UAPI_ASM_HWCAP_H */

diff --git a/arch/loongarch/kernel/elf.c b/arch/loongarch/kernel/elf.c
new file mode 100644
index 000000000000..072dfd40f0b5
--- /dev/null
+++ b/arch/loongarch/kernel/elf.c

@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author: Huacai Chen <chenhuacai@loongson.cn>
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+
+#include <linux/binfmts.h>
+#include <linux/elf.h>
+#include <linux/export.h>
+#include <linux/sched.h>
+
+#include <asm/cpu-features.h>
+#include <asm/cpu-info.h>
+
+int arch_elf_pt_proc(void *_ehdr, void *_phdr, struct file *elf,
+                    bool is_interp, struct arch_elf_state *state)
+{
+       return 0;
+}
+
+int arch_check_elf(void *_ehdr, bool has_interpreter, void *_interp_ehdr,
+                  struct arch_elf_state *state)
+{
+       return 0;
+}
+
+void loongarch_set_personality_fcsr(struct arch_elf_state *state)
+{
+       current->thread.fpu.fcsr = boot_cpu_data.fpu_csr0;
+}
+
+int loongarch_elf_read_implies_exec(void *elf_ex, int exstack)
+{
+       if (exstack != EXSTACK_DISABLE_X) {
+               /* The binary doesn't request a non-executable stack */
+               return 1;
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL(loongarch_elf_read_implies_exec);

diff --git a/arch/loongarch/kernel/module.c b/arch/loongarch/kernel/module.c
new file mode 100644
index 000000000000..af7c403b032b
--- /dev/null
+++ b/arch/loongarch/kernel/module.c

@@ -0,0 +1,652 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Author: Hanlu Li <lihanlu@loongson.cn>
+ *         Huacai Chen <chenhuacai@loongson.cn>
+ *
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+
+#undef DEBUG
+
+#include <linux/moduleloader.h>
+#include <linux/elf.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+
+static int rela_stack_push(s64 stack_value, s64 *rela_stack, size_t *rela_stack_top)
+{
+       if (*rela_stack_top >= RELA_STACK_DEPTH)
+               return -ENOEXEC;
+
+       rela_stack[(*rela_stack_top)++] = stack_value;
+       pr_debug("%s stack_value = 0x%llx\n", __func__, stack_value);
+
+       return 0;
+}
+
+static int rela_stack_pop(s64 *stack_value, s64 *rela_stack, size_t *rela_stack_top)
+{
+       if (*rela_stack_top == 0)
+               return -ENOEXEC;
+
+       *stack_value = rela_stack[--(*rela_stack_top)];
+       pr_debug("%s stack_value = 0x%llx\n", __func__, *stack_value);
+
+       return 0;
+}
+
+static int apply_r_larch_none(struct module *me, u32 *location, Elf_Addr v,
+                               s64 *rela_stack, size_t *rela_stack_top)
+{
+       return 0;
+}
+
+static int apply_r_larch_32(struct module *me, u32 *location, Elf_Addr v,
+                               s64 *rela_stack, size_t *rela_stack_top)
+{
+       *location = v;
+       return 0;
+}
+
+static int apply_r_larch_64(struct module *me, u32 *location, Elf_Addr v,
+                               s64 *rela_stack, size_t *rela_stack_top)
+{
+       *(Elf_Addr *)location = v;
+       return 0;
+}
+
+static int apply_r_larch_mark_la(struct module *me, u32 *location, Elf_Addr v,
+                                       s64 *rela_stack, size_t *rela_stack_top)
+{
+       return 0;
+}
+
+static int apply_r_larch_mark_pcrel(struct module *me, u32 *location, Elf_Addr v,
+                                       s64 *rela_stack, size_t *rela_stack_top)
+{
+       return 0;
+}
+
+static int apply_r_larch_sop_push_pcrel(struct module *me, u32 *location, Elf_Addr v,
+                                               s64 *rela_stack, size_t *rela_stack_top)
+{
+       return rela_stack_push(v - (u64)location, rela_stack, rela_stack_top);
+}
+
+static int apply_r_larch_sop_push_absolute(struct module *me, u32 *location, Elf_Addr v,
+                                               s64 *rela_stack, size_t *rela_stack_top)
+{
+       return rela_stack_push(v, rela_stack, rela_stack_top);
+}
+
+static int apply_r_larch_sop_push_dup(struct module *me, u32 *location, Elf_Addr v,
+                                               s64 *rela_stack, size_t *rela_stack_top)
+{
+       int err = 0;
+       s64 opr1;
+
+       err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+       err = rela_stack_push(opr1, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+       err = rela_stack_push(opr1, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+
+       return 0;
+}
+
+static int apply_r_larch_sop_push_plt_pcrel(struct module *me, u32 *location, Elf_Addr v,
+                                               s64 *rela_stack, size_t *rela_stack_top)
+{
+       return apply_r_larch_sop_push_pcrel(me, location, v, rela_stack, rela_stack_top);
+}
+
+static int apply_r_larch_sop_sub(struct module *me, u32 *location, Elf_Addr v,
+                                       s64 *rela_stack, size_t *rela_stack_top)
+{
+       int err = 0;
+       s64 opr1, opr2;
+
+       err = rela_stack_pop(&opr2, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+       err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+       err = rela_stack_push(opr1 - opr2, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+
+       return 0;
+}
+
+static int apply_r_larch_sop_sl(struct module *me, u32 *location, Elf_Addr v,
+                                       s64 *rela_stack, size_t *rela_stack_top)
+{
+       int err = 0;
+       s64 opr1, opr2;
+
+       err = rela_stack_pop(&opr2, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+       err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+       err = rela_stack_push(opr1 << opr2, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+
+       return 0;
+}
+
+static int apply_r_larch_sop_sr(struct module *me, u32 *location, Elf_Addr v,
+                                       s64 *rela_stack, size_t *rela_stack_top)
+{
+       int err = 0;
+       s64 opr1, opr2;
+
+       err = rela_stack_pop(&opr2, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+       err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+       err = rela_stack_push(opr1 >> opr2, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+
+       return 0;
+}
+
+static int apply_r_larch_sop_add(struct module *me, u32 *location, Elf_Addr v,
+                                       s64 *rela_stack, size_t *rela_stack_top)
+{
+       int err = 0;
+       s64 opr1, opr2;
+
+       err = rela_stack_pop(&opr2, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+       err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+       err = rela_stack_push(opr1 + opr2, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+
+       return 0;
+}
+static int apply_r_larch_sop_and(struct module *me, u32 *location, Elf_Addr v,
+                                       s64 *rela_stack, size_t *rela_stack_top)
+{
+       int err = 0;
+       s64 opr1, opr2;
+
+       err = rela_stack_pop(&opr2, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+       err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+       err = rela_stack_push(opr1 & opr2, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+
+       return 0;
+}
+
+static int apply_r_larch_sop_if_else(struct module *me, u32 *location, Elf_Addr v,
+                                       s64 *rela_stack, size_t *rela_stack_top)
+{
+       int err = 0;
+       s64 opr1, opr2, opr3;
+
+       err = rela_stack_pop(&opr3, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+       err = rela_stack_pop(&opr2, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+       err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+       err = rela_stack_push(opr1 ? opr2 : opr3, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+
+       return 0;
+}
+
+static int apply_r_larch_sop_pop_32_s_10_5(struct module *me, u32 *location, Elf_Addr v,
+                                               s64 *rela_stack, size_t *rela_stack_top)
+{
+       int err = 0;
+       s64 opr1;
+
+       err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+
+       /* check 5-bit signed */
+       if ((opr1 & ~(u64)0xf) &&
+           (opr1 & ~(u64)0xf) != ~(u64)0xf) {
+               pr_err("module %s: opr1 = 0x%llx overflow! dangerous %s relocation\n",
+                       me->name, opr1, __func__);
+               return -ENOEXEC;
+       }
+
+       /* (*(uint32_t *) PC) [14 ... 10] = opr [4 ... 0] */
+       *location = (*location & (~(u32)0x7c00)) | ((opr1 & 0x1f) << 10);
+
+       return 0;
+}
+
+static int apply_r_larch_sop_pop_32_u_10_12(struct module *me, u32 *location, Elf_Addr v,
+                                               s64 *rela_stack, size_t *rela_stack_top)
+{
+       int err = 0;
+       s64 opr1;
+
+       err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+
+       /* check 12-bit unsigned */
+       if (opr1 & ~(u64)0xfff) {
+               pr_err("module %s: opr1 = 0x%llx overflow! dangerous %s relocation\n",
+                       me->name, opr1, __func__);
+               return -ENOEXEC;
+       }
+
+       /* (*(uint32_t *) PC) [21 ... 10] = opr [11 ... 0] */
+       *location = (*location & (~(u32)0x3ffc00)) | ((opr1 & 0xfff) << 10);
+
+       return 0;
+}
+
+static int apply_r_larch_sop_pop_32_s_10_12(struct module *me, u32 *location, Elf_Addr v,
+                                               s64 *rela_stack, size_t *rela_stack_top)
+{
+       int err = 0;
+       s64 opr1;
+
+       err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+
+       /* check 12-bit signed */
+       if ((opr1 & ~(u64)0x7ff) &&
+           (opr1 & ~(u64)0x7ff) != ~(u64)0x7ff) {
+               pr_err("module %s: opr1 = 0x%llx overflow! dangerous %s relocation\n",
+                       me->name, opr1, __func__);
+               return -ENOEXEC;
+       }
+
+       /* (*(uint32_t *) PC) [21 ... 10] = opr [11 ... 0] */
+       *location = (*location & (~(u32)0x3ffc00)) | ((opr1 & 0xfff) << 10);
+
+       return 0;
+}
+
+static int apply_r_larch_sop_pop_32_s_10_16(struct module *me, u32 *location, Elf_Addr v,
+                                               s64 *rela_stack, size_t *rela_stack_top)
+{
+       int err = 0;
+       s64 opr1;
+
+       err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+
+       /* check 16-bit signed */
+       if ((opr1 & ~(u64)0x7fff) &&
+           (opr1 & ~(u64)0x7fff) != ~(u64)0x7fff) {
+               pr_err("module %s: opr1 = 0x%llx overflow! dangerous %s relocation\n",
+                       me->name, opr1, __func__);
+               return -ENOEXEC;
+       }
+
+       /* (*(uint32_t *) PC) [25 ... 10] = opr [15 ... 0] */
+       *location = (*location & 0xfc0003ff) | ((opr1 & 0xffff) << 10);
+
+       return 0;
+}
+
+static int apply_r_larch_sop_pop_32_s_10_16_s2(struct module *me, u32 *location, Elf_Addr v,
+                                               s64 *rela_stack, size_t *rela_stack_top)
+{
+       int err = 0;
+       s64 opr1;
+
+       err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+
+       /* check 4-aligned */
+       if (opr1 % 4) {
+               pr_err("module %s: opr1 = 0x%llx unaligned! dangerous %s relocation\n",
+                       me->name, opr1, __func__);
+               return -ENOEXEC;
+       }
+
+       opr1 >>= 2;
+       /* check 18-bit signed */
+       if ((opr1 & ~(u64)0x7fff) &&
+           (opr1 & ~(u64)0x7fff) != ~(u64)0x7fff) {
+               pr_err("module %s: opr1 = 0x%llx overflow! dangerous %s relocation\n",
+                       me->name, opr1, __func__);
+               return -ENOEXEC;
+       }
+
+       /* (*(uint32_t *) PC) [25 ... 10] = opr [17 ... 2] */
+       *location = (*location & 0xfc0003ff) | ((opr1 & 0xffff) << 10);
+
+       return 0;
+}
+
+static int apply_r_larch_sop_pop_32_s_5_20(struct module *me, u32 *location, Elf_Addr v,
+                                               s64 *rela_stack, size_t *rela_stack_top)
+{
+       int err = 0;
+       s64 opr1;
+
+       err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+
+       /* check 20-bit signed */
+       if ((opr1 & ~(u64)0x7ffff) &&
+           (opr1 & ~(u64)0x7ffff) != ~(u64)0x7ffff) {
+               pr_err("module %s: opr1 = 0x%llx overflow! dangerous %s relocation\n",
+                       me->name, opr1, __func__);
+               return -ENOEXEC;
+       }
+
+       /* (*(uint32_t *) PC) [24 ... 5] = opr [19 ... 0] */
+       *location = (*location & (~(u32)0x1ffffe0)) | ((opr1 & 0xfffff) << 5);
+
+       return 0;
+}
+
+static int apply_r_larch_sop_pop_32_s_0_5_10_16_s2(struct module *me, u32 *location, Elf_Addr v,
+                                                       s64 *rela_stack, size_t *rela_stack_top)
+{
+       int err = 0;
+       s64 opr1;
+
+       err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+
+       /* check 4-aligned */
+       if (opr1 % 4) {
+               pr_err("module %s: opr1 = 0x%llx unaligned! dangerous %s relocation\n",
+                       me->name, opr1, __func__);
+               return -ENOEXEC;
+       }
+
+       opr1 >>= 2;
+       /* check 23-bit signed */
+       if ((opr1 & ~(u64)0xfffff) &&
+           (opr1 & ~(u64)0xfffff) != ~(u64)0xfffff) {
+               pr_err("module %s: opr1 = 0x%llx overflow! dangerous %s relocation\n",
+                       me->name, opr1, __func__);
+               return -ENOEXEC;
+       }
+
+       /*
+        * (*(uint32_t *) PC) [4 ... 0] = opr [22 ... 18]
+        * (*(uint32_t *) PC) [25 ... 10] = opr [17 ... 2]
+        */
+       *location = (*location & 0xfc0003e0)
+               | ((opr1 & 0x1f0000) >> 16) | ((opr1 & 0xffff) << 10);
+
+       return 0;
+}
+
+static int apply_r_larch_sop_pop_32_s_0_10_10_16_s2(struct module *me, u32 *location, Elf_Addr v,
+                                                       s64 *rela_stack, size_t *rela_stack_top)
+{
+       int err = 0;
+       s64 opr1;
+
+       err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+
+       /* check 4-aligned */
+       if (opr1 % 4) {
+               pr_err("module %s: opr1 = 0x%llx unaligned! dangerous %s relocation\n",
+                       me->name, opr1, __func__);
+               return -ENOEXEC;
+       }
+
+       opr1 >>= 2;
+       /* check 28-bit signed */
+       if ((opr1 & ~(u64)0x1ffffff) &&
+           (opr1 & ~(u64)0x1ffffff) != ~(u64)0x1ffffff) {
+               pr_err("module %s: opr1 = 0x%llx overflow! dangerous %s relocation\n",
+                       me->name, opr1, __func__);
+               return -ENOEXEC;
+       }
+
+       /*
+        * (*(uint32_t *) PC) [9 ... 0] = opr [27 ... 18]
+        * (*(uint32_t *) PC) [25 ... 10] = opr [17 ... 2]
+        */
+       *location = (*location & 0xfc000000)
+               | ((opr1 & 0x3ff0000) >> 16) | ((opr1 & 0xffff) << 10);
+
+       return 0;
+}
+
+static int apply_r_larch_sop_pop_32_u(struct module *me, u32 *location, Elf_Addr v,
+                                       s64 *rela_stack, size_t *rela_stack_top)
+{
+       int err = 0;
+       s64 opr1;
+
+       err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
+       if (err)
+               return err;
+
+       /* check 32-bit unsigned */
+       if (opr1 & ~(u64)0xffffffff) {
+               pr_err("module %s: opr1 = 0x%llx overflow! dangerous %s relocation\n",
+                       me->name, opr1, __func__);
+               return -ENOEXEC;
+       }
+
+       /* (*(uint32_t *) PC) = opr */
+       *location = (u32)opr1;
+
+       return 0;
+}
+
+static int apply_r_larch_add32(struct module *me, u32 *location, Elf_Addr v,
+                               s64 *rela_stack, size_t *rela_stack_top)
+{
+       *(s32 *)location += v;
+       return 0;
+}
+
+static int apply_r_larch_add64(struct module *me, u32 *location, Elf_Addr v,
+                               s64 *rela_stack, size_t *rela_stack_top)
+{
+       *(s64 *)location += v;
+       return 0;
+}
+
+static int apply_r_larch_sub32(struct module *me, u32 *location, Elf_Addr v,
+                               s64 *rela_stack, size_t *rela_stack_top)
+{
+       *(s32 *)location -= v;
+       return 0;
+}
+
+static int apply_r_larch_sub64(struct module *me, u32 *location, Elf_Addr v,
+                               s64 *rela_stack, size_t *rela_stack_top)
+{
+       *(s64 *)location -= v;
+       return 0;
+}
+
+/*
+ * reloc_handlers_rela() - Apply a particular relocation to a module
+ * @me: the module to apply the reloc to
+ * @location: the address at which the reloc is to be applied
+ * @v: the value of the reloc, with addend for RELA-style
+ * @rela_stack: the stack used for store relocation info, LOCAL to THIS module
+ * @rela_stac_top: where the stack operation(pop/push) applies to
+ *
+ * Return: 0 upon success, else -ERRNO
+ */
+typedef int (*reloc_rela_handler)(struct module *me, u32 *location, Elf_Addr v,
+                               s64 *rela_stack, size_t *rela_stack_top);
+
+/* The handlers for known reloc types */
+static reloc_rela_handler reloc_rela_handlers[] = {
+       [R_LARCH_NONE]                          = apply_r_larch_none,
+       [R_LARCH_32]                            = apply_r_larch_32,
+       [R_LARCH_64]                            = apply_r_larch_64,
+       [R_LARCH_MARK_LA]                       = apply_r_larch_mark_la,
+       [R_LARCH_MARK_PCREL]                    = apply_r_larch_mark_pcrel,
+       [R_LARCH_SOP_PUSH_PCREL]                = apply_r_larch_sop_push_pcrel,
+       [R_LARCH_SOP_PUSH_ABSOLUTE]             = apply_r_larch_sop_push_absolute,
+       [R_LARCH_SOP_PUSH_DUP]                  = apply_r_larch_sop_push_dup,
+       [R_LARCH_SOP_PUSH_PLT_PCREL]            = apply_r_larch_sop_push_plt_pcrel,
+       [R_LARCH_SOP_SUB]                       = apply_r_larch_sop_sub,
+       [R_LARCH_SOP_SL]                        = apply_r_larch_sop_sl,
+       [R_LARCH_SOP_SR]                        = apply_r_larch_sop_sr,
+       [R_LARCH_SOP_ADD]                       = apply_r_larch_sop_add,
+       [R_LARCH_SOP_AND]                       = apply_r_larch_sop_and,
+       [R_LARCH_SOP_IF_ELSE]                   = apply_r_larch_sop_if_else,
+       [R_LARCH_SOP_POP_32_S_10_5]             = apply_r_larch_sop_pop_32_s_10_5,
+       [R_LARCH_SOP_POP_32_U_10_12]            = apply_r_larch_sop_pop_32_u_10_12,
+       [R_LARCH_SOP_POP_32_S_10_12]            = apply_r_larch_sop_pop_32_s_10_12,
+       [R_LARCH_SOP_POP_32_S_10_16]            = apply_r_larch_sop_pop_32_s_10_16,
+       [R_LARCH_SOP_POP_32_S_10_16_S2]         = apply_r_larch_sop_pop_32_s_10_16_s2,
+       [R_LARCH_SOP_POP_32_S_5_20]             = apply_r_larch_sop_pop_32_s_5_20,
+       [R_LARCH_SOP_POP_32_S_0_5_10_16_S2]     = apply_r_larch_sop_pop_32_s_0_5_10_16_s2,
+       [R_LARCH_SOP_POP_32_S_0_10_10_16_S2]    = apply_r_larch_sop_pop_32_s_0_10_10_16_s2,
+       [R_LARCH_SOP_POP_32_U]                  = apply_r_larch_sop_pop_32_u,
+       [R_LARCH_ADD32]                         = apply_r_larch_add32,
+       [R_LARCH_ADD64]                         = apply_r_larch_add64,
+       [R_LARCH_SUB32]                         = apply_r_larch_sub32,
+       [R_LARCH_SUB64]                         = apply_r_larch_sub64,
+};
+
+int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
+                  unsigned int symindex, unsigned int relsec,
+                  struct module *me)
+{
+       int i, err;
+       unsigned int type;
+       s64 rela_stack[RELA_STACK_DEPTH];
+       size_t rela_stack_top = 0;
+       reloc_rela_handler handler;
+       void *location;
+       Elf_Addr v;
+       Elf_Sym *sym;
+       Elf_Rel *rel = (void *) sechdrs[relsec].sh_addr;
+
+       pr_debug("%s: Applying relocate section %u to %u\n", __func__, relsec,
+              sechdrs[relsec].sh_info);
+
+       rela_stack_top = 0;
+       for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
+               /* This is where to make the change */
+               location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr + rel[i].r_offset;
+               /* This is the symbol it is referring to */
+               sym = (Elf_Sym *)sechdrs[symindex].sh_addr + ELF_R_SYM(rel[i].r_info);
+               if (IS_ERR_VALUE(sym->st_value)) {
+                       /* Ignore unresolved weak symbol */
+                       if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
+                               continue;
+                       pr_warn("%s: Unknown symbol %s\n", me->name, strtab + sym->st_name);
+                       return -ENOENT;
+               }
+
+               type = ELF_R_TYPE(rel[i].r_info);
+
+               if (type < ARRAY_SIZE(reloc_rela_handlers))
+                       handler = reloc_rela_handlers[type];
+               else
+                       handler = NULL;
+
+               if (!handler) {
+                       pr_err("%s: Unknown relocation type %u\n", me->name, type);
+                       return -EINVAL;
+               }
+
+               v = sym->st_value;
+               err = handler(me, location, v, rela_stack, &rela_stack_top);
+               if (err)
+                       return err;
+       }
+
+       return 0;
+}
+
+int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
+                      unsigned int symindex, unsigned int relsec,
+                      struct module *me)
+{
+       int i, err;
+       unsigned int type;
+       s64 rela_stack[RELA_STACK_DEPTH];
+       size_t rela_stack_top = 0;
+       reloc_rela_handler handler;
+       void *location;
+       Elf_Addr v;
+       Elf_Sym *sym;
+       Elf_Rela *rel = (void *) sechdrs[relsec].sh_addr;
+
+       pr_debug("%s: Applying relocate section %u to %u\n", __func__, relsec,
+              sechdrs[relsec].sh_info);
+
+       rela_stack_top = 0;
+       for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
+               /* This is where to make the change */
+               location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr + rel[i].r_offset;
+               /* This is the symbol it is referring to */
+               sym = (Elf_Sym *)sechdrs[symindex].sh_addr + ELF_R_SYM(rel[i].r_info);
+               if (IS_ERR_VALUE(sym->st_value)) {
+                       /* Ignore unresolved weak symbol */
+                       if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
+                               continue;
+                       pr_warn("%s: Unknown symbol %s\n", me->name, strtab + sym->st_name);
+                       return -ENOENT;
+               }
+
+               type = ELF_R_TYPE(rel[i].r_info);
+
+               if (type < ARRAY_SIZE(reloc_rela_handlers))
+                       handler = reloc_rela_handlers[type];
+               else
+                       handler = NULL;
+
+               if (!handler) {
+                       pr_err("%s: Unknown relocation type %u\n", me->name, type);
+                       return -EINVAL;
+               }
+
+               pr_debug("type %d st_value %llx r_addend %llx loc %llx\n",
+                      (int)ELF64_R_TYPE(rel[i].r_info),
+                      sym->st_value, rel[i].r_addend, (u64)location);
+
+               v = sym->st_value + rel[i].r_addend;
+               err = handler(me, location, v, rela_stack, &rela_stack_top);
+               if (err)
+                       return err;
+       }
+
+       return 0;
+}
--

2.27.0